/*
 * uhttpd - Tiny single-threaded httpd - Main header
 *
 *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#ifndef _UHTTPD_

#define _BSD_SOURCE
#define _XOPEN_SOURCE 700

#include <arpa/inet.h>
#include <ctype.h>
#include <dlfcn.h>
#include <errno.h>
#include <limits.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "libubox/list.h"
#include "libubox/uloop.h"

#ifdef HAVE_LUA
#include <lua.h>
#endif

#ifdef HAVE_TLS
#include <openssl/ssl.h>
#endif

/* uClibc... */
#ifndef SOL_TCP
#define SOL_TCP 6
#endif

/**
 * 将错误信息写入到标准错误中
 * 它允许你可以定义可变参数宏(variadic
 * macros)，这样你就可以使用拥有可以变化的参数表的宏。
 * #define debug(...) printf(__VA_ARGS__)
 * debug("Y = %d\n", y);
 * printf("Y = %d\n", y);
 */
#ifdef DEBUG
#define D(...) fprintf(stderr, __VA_ARGS__)
#else
#define D(...)
#endif

#define UH_LIMIT_MSGHEAD 4096
#define UH_LIMIT_HEADERS 64
#define UH_LIMIT_CLIENTS 64

struct listener;
struct client;
struct interpreter;
struct http_request;
struct uh_ubus_state;

/* uhttpd的配置 */
struct config {
  char docroot[PATH_MAX];
  char *realm;
  char *file;
  char *error_handler;
  int no_symlinks;
  int no_dirlists;
  int network_timeout;
  int rfc1918_filter;
  int tcp_keepalive;
  int max_requests;
#ifdef HAVE_CGI
  char *cgi_prefix;
#endif
#ifdef HAVE_LUA
  char *lua_prefix;
  char *lua_handler;
  lua_State *lua_state;
  lua_State *(*lua_init)(const struct config *conf);
  void (*lua_close)(lua_State *L);
  bool (*lua_request)(struct client *cl, lua_State *L);
#endif
#ifdef HAVE_UBUS
  char *ubus_prefix;
  char *ubus_socket;
  void *ubus_state;
  struct uh_ubus_state *(*ubus_init)(const struct config *conf);
  void (*ubus_close)(struct uh_ubus_state *state);
  bool (*ubus_request)(struct client *cl, struct uh_ubus_state *state);
#endif
#if defined(HAVE_CGI) || defined(HAVE_LUA) || defined(HAVE_UBUS)
  int script_timeout;
#endif
#ifdef HAVE_TLS
  char *cert;
  char *key;
  SSL_CTX *tls;
  SSL_CTX *(*tls_init)(void);
  int (*tls_cert)(SSL_CTX *c, const char *file);
  int (*tls_key)(SSL_CTX *c, const char *file);
  void (*tls_free)(struct listener *l);
  int (*tls_accept)(struct client *c);
  void (*tls_close)(struct client *c);
  int (*tls_recv)(struct client *c, char *buf, int len);
  int (*tls_send)(struct client *c, const char *buf, int len);
#endif
};

enum http_method {
  UH_HTTP_MSG_GET,
  UH_HTTP_MSG_POST,
  UH_HTTP_MSG_HEAD,
};

extern const char *http_methods[];

enum http_version {
  UH_HTTP_VER_0_9,
  UH_HTTP_VER_1_0,
  UH_HTTP_VER_1_1,
};

extern const char *http_versions[];

struct http_request {
  enum http_method method;
  enum http_version version;
  int redirect_status;
  char *url;
  char *headers[UH_LIMIT_HEADERS];
  struct auth_realm *realm;
};

struct http_response {
  int statuscode;
  char *statusmsg;
  char *headers[UH_LIMIT_HEADERS];
};

struct listener {
  struct uloop_fd fd;
  int socket;
  int n_clients;
  struct sockaddr_in6 addr;
  struct config *conf;
#ifdef HAVE_TLS
  SSL_CTX *tls;
#endif
  struct listener *next;
};

struct client {
#ifdef HAVE_TLS
  SSL *tls;
#endif
  struct uloop_fd fd;
  struct uloop_fd rpipe;
  struct uloop_fd wpipe;
  struct uloop_process proc;
  struct uloop_timeout timeout;
  bool (*cb)(struct client *);
  void *priv;
  bool dispatched;
  struct {
    char buf[UH_LIMIT_MSGHEAD];
    char *ptr;
    int len;
  } httpbuf;
  struct listener *server;
  struct http_request request;
  struct http_response response;
  struct sockaddr_in6 servaddr;
  struct sockaddr_in6 peeraddr;
  struct client *next;
};

struct client_light {
#ifdef HAVE_TLS
  SSL *tls;
#endif
  struct uloop_fd fd;
};

struct auth_realm {
  char path[PATH_MAX];
  char user[32];
  char pass[128];
  struct auth_realm *next;
};

struct index_file {
  const char *name;
  struct index_file *next;
};

#ifdef HAVE_CGI
struct interpreter {
  char path[PATH_MAX];
  char extn[32];
  struct interpreter *next;
};
#endif

#endif
